rules, tactics, strategies and history

Bishops & Knights

The game below shows a typical case of a double threat with the Queen in conjunction with other pieces. White on the move plays B-d3, and now Black cannot castle as White would continue with Q-e4 threatening mate through Qxh7 and at the same time attacking the Bishop e7 for the second time who is only once protected. Black would have to defend the mate by either P-g6 or P-f5 or Q-h5 and White would capture the Bishop.

When castling on the King side a player must always beware of an attack by the Queen and another piece on the King's Rook's Pawn.

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a	b	c	d	e	f	g	h

In the case illustrated above it was the Bishop who assisted the Queen. A Knight could aid in an attack on h7 from either g5 or f6. More frequently he does so from g5 as usually the square f6 is not accessible to him on account of the Pawn g7 protecting it. In the majority of cases the Knight goes to g5 from f3, and the Queen attacks h7 from h5, coming from her original square d1. Then, if Black cannot protect h7 by a Knight from f6 or by the Bishop, from f5 for instance, or from g6, the only protection as a rule is to advance the Pawn to h6. The position below may serve as an example.

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a	b	c	d	e	f	g	h

Black's last move was Kt-e7, while Kt-f6, which protects the Pawn h7 against future attacks, is generally preferable in any opening. White can now play Kt-g5, attacking the Pawn f7 for the second time, as it is already attacked by the Bishop c4. The student will, at this stage of his development, not yet know why Black should be so anxious to defend the Pawn f7, considering
that he is a Pawn ahead so that the loss of a Pawn would only equalize the forces but would not give White a material advantage. However, later on, when discussing the strategy of the opening, it will become evident that in the position of the diagram Black must, under all circumstances, defend the Pawn f7 as otherwise his game would soon become hopeless on account of
the exposed position of his King.

There are only two ways for Black to defend f7. One is to advance the Queen's Pawn to d5, interrupting the diagonal of White's Bishop; the other is to castle, so that the Rook procures the second protection for the Pawn f7 which is needed. It would then not be good for White to capture the Pawn because he would have to give up Knight and Bishop for Rook and one Pawn, which is not a sufficient equivalent.

Of the two ways indicated only the first one is feasible. For if Black castles he gives White an opportunity to institute an attack on the weak Pawn h7 with Knight and Queen against which Black has no satisfactory defense. Play would develop as follows:

(1) Kt-g5 o-o
(2) Q-h5 P-h6

This is the only defense against the threat Qxh7 mate. But White's Queen's move involved a double threat. It brought up a third attack on the Pawn f7, and the latter now falls, forcing Black to give up some more material.

(3) Ktxf7 Rxf7

Black has to sacrifice the exchange. If he moved the Queen, which is attacked by the Knight, he would expose his King to a deadly double check, viz.: (4) Ktxh6++, K-h8 or h7; (5) Kt-f7+ (discovered), K-g8; (6) Q-h8 mate. After giving up his Rook for the Knight on the third move Black has a lost game, for as explained in the previous chapter White can simply exchange all pieces and force the win in the ending with his superior material.